P733: TREATMENT PATTERNS AND OUTCOMES AMONG PATIENTS WITH LOWER-RISK MYELODYSPLASTIC SYNDROMES RECEIVING LUSPATERCEPT IN ROUTINE CLINICAL PRACTICE IN THE UNITED STATES
Authors: Sudipto Mukherjee, Cherrishe Brown-Bickerstaff, David Huggar, Angelica Falkenstein, Adeola Y. Makinde, Emily Bland, Jalyna Laney, Marné Garretson, Ali Mcbride
Journal: HemaSphere (2023)

Background: Luspatercept is a first-in-class erythroid maturation agent approved by the US Food and Drug Administration for the management of anemia in patients (pts) with lower-risk myelodysplastic syndromes (LR-MDS) with ring sideroblasts (RS) or with MDS/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T) who have had an inadequate response to an erythropoiesis-stimulating agent (ESA) and require ≥2 red blood cell (RBC) units/8 weeks. Data on treatment (tx) patterns and outcomes of pts with LR-MDS treated with luspatercept in routine clinical practice are currently lacking. Aims: To examine pt characteristics, tx patterns, and transfusion outcomes among US adults with LR-MDS or MDS/MPN-RS-T who received luspatercept in clinical practice. Methods: This retrospective, observational cohort study used physician-abstracted data from medical records of adults diagnosed with LR-MDS (International Prognostic Scoring System [IPSS] score of Low- or Intermediate-1-risk and/or an IPSS-Revised score of Very Low-, Low-, or Intermediate-risk) or MDS/MPN-RS-T on or after January 1, 2015 who received luspatercept for ≥3 months (or until death if <3 months of luspatercept initiation) in the US. Pts who received any tx for MDS or luspatercept as part of a clinical trial were excluded. Baseline refers to the 8 weeks preceding luspatercept initiation. Transfusion burden (TB) was defined based on the lowest number of RBC and/or platelet transfusion sessions (any units of RBCs and/or platelets received in a single day) during a consecutive ≥8-week period: transfusion independence (TI), 0 sessions; low TB, 1–3 sessions; and moderate TB, 4–5 sessions. Duration of tx (DOT) was assessed using the Kaplan–Meier method; all other results were summarized using descriptive statistics. Results: A total of 253 pts were included; 53% were male and 71% were White. Mean age at luspatercept initiation was 73.2 years. Prior to luspatercept initiation, 87% of pts received 1 tx and 89% of pts received an ESA. Median follow-up time was 5.7 months (range 2.1–34.5) and median luspatercept DOT was 10.8 months (95% CI, 9.2–13.3). Eighty-four (33%) pts discontinued luspatercept during study follow-up; most commonly due to lack of hematologic improvement (n=26/84, 31%) and disease progression to higher-risk MDS (n=21/84, 25%). One pt discontinued tx due to adverse events. Twenty-one (8%) pts were transfusion independent at baseline, of whom 95% maintained TI during weeks 1–24 of luspatercept tx (Table). Of the 208 (82%) pts with low TB at baseline, 90% achieved TI and 10% maintained low TB during weeks 1–24 of luspatercept tx. Of the 24 (10%) pts with moderate TB at baseline, 58% achieved TI and 42% achieved low TB during weeks 1–24 of luspatercept tx. Of the 232 pts who were transfusion dependent (TD; low or moderate TB) at baseline, 60% achieved physician-reported modified hematologic improvement-erythroid (mHI-E) during luspatercept tx and 24% did not. Physician-reported mHI-E status was unknown for 16% of pts. Summary/Conclusion: In this study of luspatercept tx patterns and outcomes in routine clinical practice, most pts received 1 tx prior to luspatercept initiation, and most pts received prior tx with an ESA. Additionally, 87% of pts who were TD at baseline achieved TI within weeks 1–24 of luspatercept initiation, suggesting that tx with luspatercept for low or moderate TB may have a substantial impact on TB. Consistent with the results of the MEDALIST trial, these findings provide additional evidence that luspatercept significantly reduces TB among pts with LR-MDS with RS for whom ESAs are not effective.Keywords: Real world data, Blood transfusion, Myelodysplastic syndrome, Clinical outcome